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Secure Firewall Management CenterApplication · Cisco

CVE-2016-6368

HIGH · 8.6 CVSS v3.0 Published 2017-04-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the detection engine parsing of Pragmatic General Multicast (PGM) protocol packets for Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the Snort process unexpectedly restarting. The vulnerability is due to improper input validation of the fields in the PGM protocol packet. An attacker could exploit this vulnerability by sending a crafted PGM packet to the detection engine on the targeted device. An exploit could allow the attacker to cause a DoS condition if the Snort process restarts and traffic inspection is bypassed or traffic is dropped. This vulnerability affects Cisco Firepower System Software that has one or more file action policies configured and is running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series with FirePOWER Services; Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls; Advanced Malware Protection (AMP) for Networks, 7000 Series Appliances; Advanced Malware Protection (AMP) for Networks, 8000 Series Appliances; Firepower 4100 Series Security Appliances; FirePOWER 7000 Series Appliances; FirePOWER 8000 Series Appliances; Firepower 9300 Series Security Appliances; FirePOWER Threat Defense for Integrated Services Routers (ISRs); Industrial Security Appliance 3000; Sourcefire 3D System Appliances; Virtual Next-Generation Intrusion Prevention System (NGIPSv) for VMware. Fixed versions: 5.4.0.10 5.4.1.9 6.0.1.3 6.1.0 6.2.0. Cisco Bug IDs: CSCuz00876.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A vulnerability in the Snort detection engine's parsing of Pragmatic General Multicast (PGM) protocol packets in Cisco Firepower System Software allows an unauthenticated remote attacker to send crafted PGM packets with improperly validated fields, causing the Snort process to unexpectedly restart and resulting in denial of service with potential traffic inspection bypass or dropped traffic.

MitigationApply the vendor-supplied patches by upgrading to fixed versions 5.4.0.10, 5.4.1.9, 6.0.1.3, 6.1.0, or 6.2.0 depending on the current deployment branch, after confirming file action policies are in use on affected devices.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Secure Firewall Management CenterApplication
Affected:= 6.0.0= 6.0.0.0= 6.0.0.1= 6.0.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Cisco FMC version
    Access the Cisco Firepower Management Center web UI and navigate to System > About > Version, or use the CLI command 'show version' on the appliance to confirm the installed software version
    Affected if The installed version matches 6.0.0, 6.0.0.0, 6.0.0.1, or 6.0.1
  2. Locate Snort inspection policy
    In the FMC web UI, navigate to Policies > Access Control > Intrusion or inspect the intrusion policy configuration files to identify the active Snort inspection ruleset
    Affected if An intrusion policy with Snort inspection is deployed
  3. Check for PGM protocol inspection enabled
    Review the intrusion policy or Snort configuration for any rules or preprocessor settings that enable Pragmatic General Multicast (PGM) protocol parsing and inspection
    Affected if PGM protocol inspection or decoding is explicitly enabled in the active Snort policy
  4. Verify network exposure to PGM traffic
    Determine if the Firepower device is configured to inspect inbound or outbound PGM protocol traffic, or review network flows to see if PGM packets could reach the device's inspection engine
    Affected if The device is configured to process PGM protocol packets through Snort inspection

You are affected if your Cisco Secure Firewall Management Center runs version 6.0.0 through 6.0.1 and has PGM protocol inspection enabled, allowing untrusted PGM packets to reach the Snort detection engine.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied patches by upgrading to fixed versions 5.4.0.10, 5.4.1.9, 6.0.1.3, 6.1.0, or 6.2.0 depending on the current deployment branch, after confirming file action policies are in use on affected devices.

Fix this in Secure Firewall Management Center Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-6368 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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